What do you say when someone says "You don't bother me at all"?

[Anonymous]

I had a problem today and my friend helped me out even though he was still at work. My problem had to do with the place he works at but it wasn't really his obligation to help me out so much. I went to his workplace and his manager gave me a number where I could call to fix my problem. Knowing that I hate talking on the phone because my English isn't that good, he called where I needed to call and fixed everything for me. After my problem was solved I texted him the following, "Thank you. Sorry for being such a bother." He answered saying "Haha no problem. You don't bother me at all" English is my second language so I don't know how to reply to this. Any sugestions?

[Pyrofox]

No problem is the US English slag way of saying your welcome its extremely informal and doesn't make much sense when one stops to think about the phrasing.

[Polocrew]

"Oww thnx"

[Cmasterson]

It just means you didn't cause him any problems really.