The Costa website lauds their coffee:

Costa Coffee

Some people would call our pursuit of the perfect cup of coffee an obsession. Do we care? No, because nothing less will do. Our Italian Master Roasters (the only three in the UK) spend their lives selecting the finest beans and roasting them to perfection. To prepare our coffee with any less care and attention to detail would be sacrilege.Our baristas are trained (some might say indoctrinated)

and

Cappuccino Single Shot Frothed Milk Chocolate Espresso topped with steamed, frothed milk and a sprinkling of chocolate: breakfast coffee you can enjoy all day.

Listen to me Costa Coffee, I am sick to death of your foul buckets of milky yuk. A cappuchino is a shot of coffee with a topping of foamed milk. Not a cup full of hot milky coffee topped off with some foam. That’s the strange thing that you call a latte. When it is pointed out to you that the thing you have just made me is not what I ordered, it should be well within your capability to make me a cup of coffee and foam. But no, you hand me another heavyweight cup of milky yuk with a nice smile.

So, Mr Whitbread, train your baristas. If I spent my life selecting beans and roasting them to perfection and then came to the London Road Costa for a cup of joe, I think I’d commit suicide there and then. Follow your own guide. According to your corporate HQ (reading from a manual with no understanding of the real issues), your cappuchinos should be 1/3 coffee, 1/3 milk and 1/3 foam. Now, that sounds to me like an abomination in its own right - but you can’t even make them like that.

And tell your redshirted managers that although they think they know how to make coffee and although it looks quite simple, they really have no clue and shouldn’t be allowed near the machine … at these prices, it is an insult.

(Just to do a pre-emptive apology, there are one or two trained baristas who do make me something lovely when I ask. You know who you are)