How to calculate earn % with fee that will be refunded later?

Let say I want to earn a fixed perc X for a trading (buy+sell, market order). Here’s my actual formula which cover also the actual fee:

const perc = 0.5;
const fee = 0.1;
const feeNormalized = 1.0 - fee / 100.0;
const percFinal = (((1.0 + perc / 100.0) / (feeNormalized * feeNormalized)) * 100) - 100;

So, for example, if I want to earn a real 0.5% (with fee of 0.1), I need to sell the buy quantity with a +% of 0.70.

Now, what if the fees (after the trading buy/sell is finished; such the next day) are refund? (i.e. vouchers in Binance).

Which is the formula to actual get 0.5%+ considering the fee when buy/sell (so less quantity) and their come back later? Can’t deal with a hypotetic fee of 0.0, since, as said, the actual quantity is less at the time I trade, and in the end the earn is not 0.5%, but a little less.

Thanks for any tips.