Have to pay R90 to change my cellphone number? Rather choose FiveStar

Need to change the cellphone number linked to my dog's microchip, and only just discovered I have to pay to update his info? Truly wish the vet who put the microchip in would have warned me. Would have rather chosen FiveStar microchips over this. Already paid a lot of money for the peace of mind, now I need to pay more? Will be contacting my vet to get this microchip removed and will be switching to a different brand. Ridiculous. So if my dog runs away, thats it? No one can contact me because my number has changed? Seriously shocked.