Automatic Transmission Torque Converter problems of the 2011 GMC Sierra

In 2017 before my vehicle completing two years from the date of purchase at (70,000 km) the vehicle start shuddering when accelerating at low speed, when the service was due I took the vehicle to dealer for service & complained about the shuddering issue, after diagnosing the vehicle they said that they have to replace the torque converter, so they did replace the torque converter under warranty after fixing the torque converter issue I found trace of oil in front driver side & again when the service was due I complained about the leak, after diagnosing the found that the shock absorber is leaking, but they didn't replace it because it's not covered by the warranty as they said it's considered as consumable parts, very strange for a shock to leak in less than three years considering that I didn't even drive it in offf road, & this is not the first vehicle I own, all the vehicles I owned didn't leak for twenty years, sorry I know it's consumable part but I am not convinced by these words, there must be a problem with the shocks, anyway I decided to not replace it with the oem shocks I installed four new after market shock, no more problems with the shocks till today. In q4 last year 2019 the transmission shuddering issue started again & when I took the vehicle for service I raised a complain again for shuddering issue, this time they said we don't have to replace the torque converter we only have to flush the transmission fluid with new oil, I think it's mobil 1, & I have to pay for that because again consumables & not covered by the warranty, hey wait a minute yes I brought the vehicle for service plus the shuddering problem but the transmission fluid is not due yet for change if you have to flush the transmission to fix the problem then do it, but don't charge me because of the manufacturer fault.