296138 DNS help needed

I need help of someone experienced in DNS matters. The problem I encounter is connected to DNS information propagation I suppose. I moved to another ISP and changed IP address of my server about 7 months ago. The dns information at my primary and secondary DNS servers was changed and changes propagated over the net in about a week. BUT some DNS servers seems to still use old information and redirect queries to the old IP. I suppose overall loss is about 10-15% of traffic. It seems that situation is not going to be solved by itself. I need your help and ready to pay if you will show me the way to solve the problem in 5-10 days.