Overhead line problems between Coventry and Birmingham and a freight train awaiting crew at Northampton causing massive disruption to trains between London and Brum today.
Try Marylebone to Birmingham Moor Street then. Cheaper.
You can also then get a train back from Moor Street to Bordesley (only open on match days, and ten/fifteen minutes walk from St. Andrews). They might even be stopping the London trains at Bordesley, but I don't know if they do.
Anyone with a London Midland ticket - these are being accepted on the Chiltern line service from Marylebone too. You can also use your ticket for getting the tube from Euston to Marylebone. It's says on the LM service the delays will last until 6pm.
If you haven't set off yet, although a longer journey, I have gone via Southampton in the past. The only trouble is they have changed the time table lately so is about a 40 minute wait for the connecting train at Southampton Central. The train is direct from here and goes via Reading & Oxford avoiding the line with the issue.