Boyfriend help??

So I’ve had some issues with my boyfriend. March of 2016 was the first incident. I had fallen asleep on my bed after getting out of the shower, he was next to me and we were just laying there hanging out (not doing anything sexual) I was in a robe because I hadn’t even changed yet and my hair was still in a towel. I woke up to my boyfriend having sex with me while I was sleeping. I was extremely grossed out and confronted him. He was ashamed and promised not to do it again. The amount of times he has done sexual things to me while I’m sleeping is unacceptable. Ive lost track of how many times this has happened. And it’s not always sex I’ll wake up to him fingering me etc even when I say no. A couple weeks ago he was in the mood but I wasn’t st all. I politely said no please not tonight. I really wasn’t feeling it. He continued anyway even though I had said no. Why does my boyfriend never listen when I say no? He acts like it is no big deal..