Shocking Customer Sevice

Absolutely shocking service from them after being a client for more than 20years. I changed to a MTN LTE package from their Rain offer due to speed issues that couldn’t be corrected and I have been battling to get connection since the 1st of April. Each time I ask for a call back no one ever calls back and even asking for a manager to call me I am still waiting. I am shocked by their lack of service especially during a time I needed it for work purposes