Number disappeared

I was due for an upgrade so I decided to get a new contract provided that I would not cancel my existing contract due to benefits that were still remaining. The consultant agreed that I would not need to cancel my existing contract since I still had benefits remaining. I requested that my existing contract number be transferred to my new contract once my benefits from my existing number were exhausted. This would've been at the end of Nov 2015. She agreed but deleted my existing contract number and gave me a new number for the existing contract. She then realized she made a mistake and tried to request the number back but was unsuccesful. She was meant to let me know of her attempts to get my number back but after two weeks I went to the store and the same consultant sheepishly informed me that she could not retrieve my number. I would like to get my number back as I've had it for over 5 years.