purchased a new geyser with 2nd HAND ELEMENT

on the 5th of May I purchased a new geyser and paid R1812.00 it was installed for used during the week of the 20th to the 25th of June and on the 26th I discovered that the water was not warm when the tenants complained that the water was not warm, I checked and confirmed their complained. I called in the electrician and he did a check on the wiring which was not faulty and did the next step and checked the element only to discover that it was a non working 2nd hand element inside the geyser. there are several dry water marks on the element which can never be collected as it was only fully operated on the 25th of June 2015 and such amount of dry water can never be accumulated with in 1 month since date of purchased. I paid a lot of money for the geyser, plumber and the electrician and feel **********ed by BUCO.