execution of sale

Please can someone from Nedbank assist, We have a property which now has a sale of execution yet as there was an errant tenant at the property they took the summons and did not report anything to us and we were unaware of any action being taken against us. We decided to sell the property after this bad experience, we have someone who has made a fair value offer and signed an OTP. Yet we have not been able to get a stay of the execution of sale, please can someone urgently assist as the execution of sale is in two weeks(14/03/2019)