Shirt Repair Help Needed

[Five and In]

A couple of months ago I bought a load of football shirts at a boot sale on a really hot, sunny day (This is relevant lol)
The "plastic" sponsors logo on one of them in particular had got quite sticky due to the heat.
I assumed that this would sort itself out once it had cooled down and hung it over the back of the door.
Two months later, it is still there and still tacky.
Is there anything I can do to help the process or is it destined to stay over the door forever?
Any help appreciated as always.