Before condemning your transmission, you should have it properly diagnosed by a shop that is familiar with the VW DSG transmission.
Sometimes a fluid leak, faulty engine sensor or transmission speed sensor, solenoid, temp sensor, or poor circuit connection can cause these types of problems.
We utilize the latest VW/Audi diagnostic equipment and would be happy to accurately diagnose the problem before you spend a lot of money by replacing the complete transmission unnecessarily. Feel free to contact me at the shop if you have any questions.
P.S.: We are finding a lot of 1.9 PD BRM TDI engine failures lately due to the use of incorrect engine oil. YOU SHOULD ONLY USE ENGINE OIL MEETING VW OIL SPEC: 504.00/507.00. This oil is generally not available at most parts stores or Oil Change "quick lubes". We recommend using Motul specific 5w40 504.00/507.00 engine oil for these applications and OEM Mann oil filters which we keep in stock.