Bolt Taxi Service Nelspruit

I have had 2 bad experiences with the Bolt Taxi services. I requested a ride in December to drop my son off at the bus station to catch the bus from Nelspruit to joburg. The taxi driver immediately called me to confirm the address and assured me he would be here to collect my son within 2 minutes. After 15 minutes he still wasn't here I called him 6 times and he rejected my call everytime. I then had to book another bolt taxi and he arrived within 5 minutes, however by the time they arrived at the bus stop the bus had left already and my son had already paid R400 for his bus ticket. He had to come back home which cost an additional R100 He then booked another bus ticket the following day and we booked a bolt and he was taken to his destination without any problem. In January I once again experienced a problem where I booked a bolt taxi as my son was ****** and in a state of shock and the taxi driver called me to confirm the collection address and the drop off address, I explained to the driver what had happened and he reassured me he was in the street of my sons place of work. However 40 mins later I called the taxi to confirm whether he had collected my son as he's place of work is approx 10 mins from home, there was no way of contacting my son directly as he had been ****** and he's phone was ******. When I called the driver he answered and I asked whether he was able to find my son and how far they are from home, he immediately dropped the phone in my ear. I called back several times and he ignored my calls I also sent a text message to which I still haven't received a response. My son was in a state of shock and ended up walking home as the Bolt did not pitch up to collect him. I laid a complaint with the Bolt Taxi service support department and the next day they contacted me via sms and apologized for the inconvenience and said that they are giving me a complimentary voucher of R100 for the inconvenience. I was told this voucher would expire in November 2021. Upon trying to redeem the voucher I received an error on the app to say the voucher isn't valid.