Back in '92, United and Delta split Panam's routes. I had a lifetime Clipper Club membership as you do and was given:
- 3 year membership to United's Red Carpet Club. 8/92 - 8/95
- Lifetime membership to Delta's Crown Room Club.
However, I learned about these only in 1994 (thats what I call delayed mail) and was able to use the United's RCC for a year and continue to enjoy the use of Delta's CRC till .....
I have yet to receive the new CRC membership cards though. I would definitely pursue the issue with both United & Delta and get what you deserve