Reargate does not open – How and where to repair?

Hello in the round, in three weeks I have to separate myself from my Phaeton, he goes back to the leasing company. Unfortunately, some repairs are still to be carried out, which are excluded from the warranty services for a reason that I cannot explain. A defect is particularly expensive and I hope someone can give me advice on how to get it cheaper. For some time now the electric tailgate has not opened and closes properly. The second cylinder as well as the engine work perfectly, only the one cylinder seems to cause a blocking. Now, however, both oil pressure cylinders as well as the engine should be replaced. Costs for the parts 1.415 Euro + pay 160 = 1.575 Euro net! Does anyone have an idea how to get it cheaper? I live in the Ruhr area, maybe there is a free workshop with special expertise here. , which you could visit. Maybe this even has a paint shop ;-). First of all thank you for ideas!