Hello Rix,
The payout value is always depending only on the level you hit and never had any relation with your investment.
If level 125 positions should give 100 M payouts, then they'll never give more (nor less), regardless of what you spent (paid the bank back) to trigger the payout.
As Alyona explained, the value to pay back is only depending on your previous payout.
Once the bank is paid back, if you're looking for a bigger payout value, then your only possibility is to hit a higher level position.
I agree you used to get higher values before they fixed the bug, but it still didn't have any relation with your investment. In fact, you were getting the partials you should have gotten if you had finished off the other positions instead of leaving them unfinished to one bar.
These partials were erroneously paid along with the fixed (almost : it can vary from + to - 7.5%) payout value, thus exceeding the originally planned values.
Then you could finish off those one bar weakened positions and get the related partials a second time.
This is where the bug was, and you were actually exploiting it.
As a result, payouts are only back to normal now.
On the other hand, don't forget that the partials you can still get by finishing off the weakened positions (usually with residual troops) will still give you partials that are still part of your total gains.
In addition, their values are much more random, and they can sometimes be as huge as half a standard payout value for the related levels.
However, I regret they lowered them a few months ago, probably as a first attempt to minimize the bug's effects.
Now it's fixed, I wish they would be made back to their original values, as now, outside payouts, the losses are too huge compared to the too small compensations we get.
Alyona, do you think this would be possible, please ?