You say "certainly exist" and then you admit you don't even know how long they are kept. Do you know what "certainly" means?
Call your cell company and ask and then tell me they are kept for 8 or 9 years.
Sarbanes - Oxley went into effect in 2002 and only requires a 7 year retention period.
IF those records exist it would be VERY unusual as corporations like to destroy everything that has expired any required retention period.