Yossi Synett vs. T-Mobile

T-Mobile offers two daily rate plans:
$2 per day - Unlimited Minutes/Text/Data
$3 per day - Unlimited Minutes/Text/Data plus first 200MB of data at up to 4G rates

Yesterday I changed my plan from the $2 per day to the $3 per day, instead of being charged an extra $1, I was charged the full $3. Since I found no benefit in the more expensive plan, today I decided to change back, and again, I was charged an extra $2 despite the fact that I had already paid $3 which included all the features of the $2 plan.

By my calculations I'm out $4 due to the unfair practice of double charging when you make a change.

When I tried to address this with customer service their answers seemed to indicate that they didn't understand my complaint and were being read from a script.