VM has 30 days, from the time when your service was restored, to credit you with any auto-comp that might be due.
VM gets two clear working days to fix a TLS fault before any compo applies. If VM fails to fix the TLS fault by that time, you get an initial payment of £9.76 to cover the first few days of the outage (the payment trigger time). After that it is £9.76 per full calendar day until the fault is fixed.
Based on that, the £40 might be the right sort of figure but would not be exactly £40 from the rough days you have outlined.
Work out exactly what you think you might be due based on the auto comp rules depending on exactly when you had your TLS and how long it lasted for. We see regular topics on here where VM offers lesser 'goodwill' payments instead of the correct auto comp figure. You will need to work it out with the exact dates in your case to see if you are being short-changed or not.
If you are talking about a TLS it would be for your broadband service, rather than loss of wi-fi, as there are no guarantees or compo for wi-fi alone
