Mango flight delay norm

Are we just unlucky or is there a Mango norm showing its ugly head? On 26/04/2018 the 19h00 flight from Cape Town to OR Tambo delayed for 2.5 hours. Technical problems with aircraft according to client service line. Convinced myself it is just this once. On 02/05/2018 the 06h30 flight from Lanseria to Cape Town. Delayed for 2 hours. Mango helpline did not even know about the delay let alone the reason. Twice in 6 days different routes, different times, is this just unlucky? I get the idea it is the Mango norm. I have since decided that it is time to try the other airlines and give Mango a chance to recover from this illness. I have written to their complaints address. Not even an acknowledgement or explanation.