dont want to do a sim swop

after having number for over a year and this being about my 5th sim swop for nthe year , they tell the number does not belong to me . my salary is being paid into it today and i have ewallet transaction coming througfh as well , they ask the most stupid questions , that nobody would actually remember . then I bought a sim card card still in the packging and they tell the sim card has been rica already , what is up with that