I forgot to take my Oyster card with me a few days ago and I travelled on my contactless credit card. Is it possible to get a refund, based on the fact that I have a monthly ticket on my Oyster? If so, how do I get it done?
Yes, you can try to get a refund. Based on TFL's site:
If you have a valid Travelcard or Bus & Tram Pass on your Oyster card and leave it at home or temporarily mislay it, we will consider giving you a refund.
You must provide original tickets or receipts for the fares you paid on the day and we will refund you the pro rata day value of your Travelcard or Bus & Tram Pass.
You can't get a refund if your Oyster card:
* Was used on the day
* Only has pay as you go credit on it
You can only claim this refund up to twice in 12 months.
You can also get a refund if you accidentally touch in with your contactless card instead of your Oyster card.
If you haven't done it, you should consider registering your contactless card on TFL's Oyster and Contactless Account site (where you should already be registered as you have a monthly travelcard on your Oyster), so they can check your travels on your contactless card as well as your Oyster.
The phone number you have to call is 0343 222 1234