I am the seller on Aliexpress, so here are some tips for you about how to contact the seller.
1. Speak English clearly if you can; if not, use Google translate.
2. Contact them in the working time: From 9: 00 AM to 19:00 PM, the time difference between Russia and China is about 4 hours. And seller always still on duty on Saturday.
3. Use the instant chat tool. if the service people is online, you can get your answer in minutes.
4. If you have urgent issues,and they do not answer you in time, send them message to ask for Skype or other. And you can talk to them in more convenience.
If the seller are serious with business, they will answer in time.
Hope it will help.