Cannot use my R2000 voucher

So I bought a R2000 voucher 4 weeks ago and I cannot use it. Every time I want to book a ride using the voucher I cannot use it always gives me an error saying go to help.com and I have been complaining to Uber everyday for the past 4 weeks and I have not been helped which bad for a company at there level and every time I send a message I am just left on read with no customer service helping me at all. I can’t even book normal rides which is really frustrating as I need this as my primary transportation on a day to day basis.