Still cant buy rp

Alright...so I bought rp at 8/12 and I needed a little more unfortunatly , currently its 8/18 and I still cant buy rp as the same thing shows up "You have encountred and error please try again later" I have been told to wait 5 days but here u go Riot plz im doing something good here giving you money so please fix that also does any one have solutions? Thankyou!