Old Mac died, new Mac won't recognise activation key. URGENT UNI Assignment need help ASAP please!!

Hi

My son's Mac died so Apple kept it and gave him a new one. Everything from the old Mac was transferred to the new Mac by restoring from a Time Machine backup. When he tried to open Parallels it asks for his activation key. He put this in but got the message "Your product activation key reached it's activation limit and cannot be used to activate Parallels Desktop". This activation key has only been used twice so we know that it has not reached it limit of 10 activations.

I presume that the issue is because it is not recognising the serial number of the new Mac. We were not able to deactivate the code from the old Mac because Apple just kept it.

My son is a university student and is working on an assignment now which must be submitted soon and he must have Parallels working ASAP because the nature of the current subject means he cannot work properly on his assignment without Parallels so this is absolutely urgent he gets Parallels working now.

I cannot find any mans of phoning Parallels other than paying for a support ticket. Surely there should be some way of resolving this without having to pay more money.

I would greatly appreciate anyone's help.

Thanks

Anne