Poor after sales assistance

I ordered a bank sized router online, I received a A5 sized router. Called over six telkom numbers in order to return it no help each of those numbers I called referred me to another number. Decided to go to the store they also gave me a number to call with no help. I still have the unopened package and I will probably be billed for something I am not using. I do admit my role in this for not opening the package whilst the delivery guy was there but I didn't expect a wrong order. They are not even responding to my emails.