I got 6 months 50% off on my plan because the employee didn't seem to care which discounts he hands out xD (rule)

I am going to try not to write yet another wall of text

• I was supposed to get 3 months 50% off after adding my student card to transport system that I've already been using
• An employee told me it indeed doesn't really work and just gave me 3M 50% off code from some spreadsheet
• I tried to activate it nearly a month later, at which point it had "expired"
• I contacted tech support, they told me they don't know about such offer, nor there being any spreadsheets with discounts, and instead offered me 50% for 1 month (possibly from the friend referral program), or that they could try opening a case which may take 30 days (basically urging me to get that 1 month)
• I went out again to find that one single very specific employee who knows what I am talking about. He gave me another code from the spreadsheet. I warned him that it's for 6M, not 3M. "Whatever, so you get 3 months more", he said smiling.

There goes unlimited data for EUR 10.25 / month.