I am very sorry for the problems you have had with this promotion. Unfortunately Wyndham changed data suppliers mid way through this offer and they have been unable to re-supply us with the file from during this promotional period.
We have now been given the ok to add these miles manually and I can confirm the 20000 miles you were due have been added to your account this morning, you should see these if you view your statement. The base miles are only awarded for additional stays after the maximum 20k have been earned.
If you have any further questions, please do not hesitate to contact me.