Wimmy, don't worry- it's quite easy.
There are 4 coils in the TS engine. Coils no.1&2 provide spark to the spark plugs for power, and coils 3&4 provide power for the emissions spark plugs, (8 plugs altogether).
Coil 1 gives a power spark to cyls 1&4.
Coil 2 gives a power spark to cyls 2&3.
Coil 3 gives an emissions spark to 2&3.
Coil 4 gives an emissions spark to 1&4.
Therefore, we can be fairly sure it is related to coils 1 or two or their leads or plugs.
There are still HT leads from the sides of the coil, and they are also suseptible to deterioration and damage (like trapping).
Why didn't you say to the garage when it went in the first time? As the engine cover and coils come out to do a cam belt, it would have been 5 minutes for your garage to check then.
You could try swapping coils 1 and 4 (no.1 coil duff).
Then coils 2 and 3 to see if that cures it(no 2 coil duff).
If not, suspect spark plugs or the leads. You could remove the spark plugs to see which does not appear to be firing, although you will need a certain amount of experience to determine that.
It could be a duff cam cover gasket which has leaked oil down the plug bores also. These engines are prone to water induced misfires if the car has been through fairly deep puddles and has no undertray.
BTW, only use the coil swapping trick as a temporary repair. If the emissions plugs do not fire, it is possible it could cause further long term problems such as a management code, so get a new coil even if this works, and remember which one is duff.