Sonas Pena Comfort toilet

Sonas Pena Comfort height open backed toilet & soft close seat pan only together with Sonas Base cistern. Bought these few days ago on Adverts - after dry fit by plumber yesterday we realised the toilet too long in protrusion and too high for the tight space - plumber absolutely convinced the cistern can work with a little bit of effort however time pressure means another toilet is required and this has to be gone in next day or two.