Well I'm answering your Question here based on the following assumption:
Your husband has given you talaq at least 3 times and he wasn't in anger in any of them he is denying it. And you shouldn't have any doubt about any time he gave you talaq!
The shari'a PoV shortly
Usually you should know that scholars will in first place listen to the husband and ask him about the issue, as it's the husband who gives talaq.
But that doesn't mean that he isn't lying or maybe he just forgot it.
So if you are convinced of what you pretended: then normally after the 3rd talaq you should refuse him, separate and leave him -if possible- and try to prove that talaq happened (if you have at least 2 witnesses) or khula' as he became a foreigner for you as he is -from a shari'a point of view- no more your husband, so he shouldn't see you uncovered neither have intercourse or any kind of relationship which is haram with a foreign man!
An important advice in talaq matters you should in any case consult a scholar!
Some Fatawa and details
So far i only found fatwas in Arabic:
- A fatwa where the husband gave two times talaq before and made an oath to menace his wife with 3 times talaq if she did something he disliked ... here the scholar says the 2 talaqs count, the 3rd (occasion) counts for some scholars, while others apply the ruling for oaths ... the husband should fast 3 days! He added a statement of Imam Ahmad:
"About a women pretending that her husband divorced her and doesn't
have any witnesses while her husband denies. He (Imam Ahmad) said: the
saying is what the husband says, but if she doesn't have any doubt
about him having given her divorce and it was the 3rd. She can't stay
with him and flee from him and release herself with money (khula')!"
- In this fatwa a man gave 3 times talaq to his wife after 30 years of marriage, while he is denying and he refused giving her talaq in front of the mufti/court ... again the scholars answered that the woman should flee from her (former) husband if she can and should act with him as with a foreign man if she has no doubt about being given 3 times talaq and he also explained that it's not necessary to have witnesses (or court etc.) for the talaq to be legal as the Verse (65:2) is explaining the matter which needs witnesses:
And when they have [nearly] fulfilled their term, either retain them according to acceptable terms or part with them according to acceptable terms.
"according to ibn Taymiya! while Imam a-Shafi'i said that he didn't know of any scholar pretending that a talaq (that occurred) without witnesses is haram!"
- In this fatwa a man is asking about his wife who pretends ha has given her 3 times talaq while he only admits 2 of them. Again the scholars said the saying is what the husband said unless she had 2 upright witnesses. Imam Ahmad even refused the option of two female and one male witnesses! Again if the woman is sure to have heard the talaq 3 times she should flee -if she can- and refuse having intercourse etc.
He also added that some scholars said if the woman had one witness the man should make an oath, if he refused then she has to make an oath and would be divorced based on this hadith from Sunan ibn Majah (which is qualified as da'if) which is also in Sunan a-Daraqutni! Ibn a--Qayyim said that all scholars and the four sunni madhabs accepted the paper of ibn 'Amr ibn Shoaiyb from his father from his grandfather (the narrators of the hadith) except a few like ibn Hazm and abu Hatim al-Busty...! Imam Malik instead accepted -in al-Mudawana- two upright female witnesses based on this hadith! So if the man accepted to make an oath this would invalidate the one witness if he rejected that would support the claim of the woman/wife!
And Allah knows best!