Ad Hoc report IF function does not show terms, only works with numbers

[ruben94-7-1]

I want to create a cross table with terms however the IF expression only works with numbers. Please see working function below:

IF(Contains("Service Type",'Delivery'), 1, IF(Contains("Service Type",'GoParrot - Delivery'), 1, IF(Contains("Service Type",'GoParrot - Take Out'), 3, IF(Contains("Service Type",'Take Out'), 3, IF(Contains("Service Type",'Dine In'), 0, 4)))))

Instead I want to use use terminology rather than numbers:

IF(Contains("Service Type",'Delivery'), ‘Delivery’, IF(Contains("Service Type",'GoParrot - Delivery'), ‘Delivery’, IF(Contains("Service Type",'GoParrot - Take Out'), ‘Take Out’, IF(Contains("Service Type",'Take Out'), ‘Take Out’, IF(Contains("Service Type",'Dine In'), ‘Dine In’, ‘Third Party’)))))

Could the the quotation (') be a factor in the expression?

I hope somone can help me.

Ruben K.