Poor service Momentum

Good day, I made a withdrawal on my Momentum policy (two-pot), but when I needed to sign the contract, I saw that an old Cellphone number was used. I changed the cellphone number, which was confirmed by a consultant, but my OTP still goes to the number not in use. I have been directed to call the Technical Help Desk for assistance, but nobody can help me there. I have sent an email to support with all my details, and they said they will come back to me within 2days, nothing yet. I have called 5 different numbers from Monday till today (thursday), but I can't find anybody who can assist me. I know that the company has a high call volume, but this is not acceptable. I just need to change my cell phone number on my online profile, to sign the contract. Can somebody please assist me.