Ridiculous used my number for years but told it does not belong to me it belongs to someone else

I have been using Telkom for many moons. I lost my sim card unfortunately and when i went to do a sim swap at both Telkom contact and Direct both just told me my sim is registered on someone elses name i have to come with that person. When i asked who the person was it was not someone near i could identify, clueless as to whom it is.. this is ridiculous i used this number for years. Bear in mind everything i have every signed onto i have used this number banking, mails, investment's ect and now its just gone and am told to come in with this lady i have no idea whom it is to do bio-matrics in order for me to retrieve my number back.