We do re-checks with suppliers, however it's an ongoing process and can take some time to go through the thousands of suppliers we have listed. If you would both like to let us know the suppliers you are having issues with, we'll be happy to follow up with them on your behalf.
I should also mention, it's always a good idea to try all methods of contact available when emails are not being responded to (if they have other avenues available, such as phone) It's a shame, but some suppliers won't treat email inquiries as priorities and if busy, are known in may cases to just ignore them altogether. It's bad business practice to do it, but for some reason there are those that do.
Anyway, let us know who these are and we will follow up and see what the issues are.