Show Flat Rate, Hide other shipping methods

Hi,
I am using the Flat Rate Shipping component of Woo Commerce, alongside the Ozpost Plugin. Both serve my requirements almost perfectly.

I am using my Transdirect account within Ozpost plugin and it is working better than expected. (Unlike the actual Transdirect Plugin which is completely useless).

The only issue I am facing is that I have set up Flat Rate Shipping in Woo Commerce. While the Ozpost plugin shows the Flat Rate cost which is awesome, it also displays the Transdirect shipping costs (Ozpost), even when a Flat Rate applies.

In short, what I need to do is hide the Transdirect quotes from Ozpost, when Flat Rate Shipping is used as a Shipping Method. If Flat Rate does not apply, then I would like the Ozpost plugin to kick in with the Transdirect quote.

The Ozpost plugin does not appear to have a function which allows me to hide its quotes when Flat Rate Shipping is present, though interestingly it is overrode by Free Shipping.

Is there a way to make Woocommerce ignore the Ozpost plug in, when Flat Rate is a Shipping Method?

Any help would be appreciated.
Thanks