Bad treatment, customer of 20 years

<p>I recently renewed my contract. I travel extensively for work and have never had a capped airtime limit. I just pay my bill, whatever it is by debit order each month. After receiving my new phone, while talking to a customer I got cut off, as my airtime had "run out". I have made numerous calls to MTN, including a credit controller. Last week, I got cut off again while talking with a customer. Thisis now a few months into my new contract. Please, how can I get the same treatment I have always enjoyed with MTN, i.e. no of high airtime cap? For the first time in my life I keep having to top up.</p>