To my knowledge, you can only use the SWIFT details for transfer from accounts under your own name but not for recieving payment from third parties.
However, while this maybe an issue, also notice other non-license banking providers do the same may be down to money laundering regulations.
Even the transferwise borderless account which provides you with an EU, US and UK account will not allow SWIFT payment in.
For non-banks, for SWIFT transfers they have to use other third-party banks which come with restrictions. In the above example Revolut is using Lloyds, as Revolut now have a EU banking license this may change over the coming months.
Keep an eye on starling, who is about to offer business banking, at the moment their current account will allow SWIFT but not SEPA. So using Starling business account once available in conjunction with revolut may be your best bet.
Revolut do offer a 30 daystrial, and as with every product you need to read the small print and make sure the product is fit for purpose. So in Revolut defence, they did provide you with a 30day trial so you had every opportunity to review their product.
If I was you, cancel the account on 12 months and accept your losses. You could refuse to pay them, and they are unlikely to take you to court but the impact on your credit rating will cost you a lot more than the £300+.
In the long term with Revolut new banking license service, in theory, services should start to imporve, but let this thread be a warning to those who are considering revolut as their main business account.