In reply to Dirhaelar: wearing different thickness socks may help but IMHO heel lift is more to do with ankle to boot shape plus the rake or angle of the boots at the back can help, more rake tends to help with heel lift cos the ankle is prevented from lifting.
If you bought them locally I would go back to the shop and go through your concerns. Any shop worth it's salt will help.
Did you have them fitted in the shop or just buy them online or something? If you had them fitted then definitely go back to the shop.
My other half suffers from heel lift due to having narrow ankles. Have to fix this with boots with a good rake, good fit around the ankle and correct lacing.
HTH Davey