BROKEN Robert Welch knife

I own a Robert Welch knife (with a Lifetime Guarantee) that was purchased from the Foschini @home store in Port Elizabeth Moffet on Main store, in the week before Christmas 2017 (19-24 December 2017). This knife slid off the table, as any normal cutlery item could and broke in half. I have never put the knife in a dishwasher, and if i use the knife, which is once a week on average i wash and dry it immediately. When i emailed the picture as i was told to do, i had to follow up and was told by the Canal Walk staff that the guarantee is only valid for manufacturing faults!!!! I was not spoken to in a professional manner, it is clear that the staff member was merely repeating what he was"told" to say to me. Firstly, for something that has a lifetime guarantee, to break on a small fall and is under 6 months old, that is ridiculous???? i did not run over this item with a car or throw it? i was NOT negligent at all!!!!! secondly, i worked for the Foschini group for 6 years and this is NO way to treat your customers!!!! the Must be a manufacturing fault for something that has a so called lifetime guarantee to break like this?????? I expect much better customer service from this group as well as a replacement knife. VERY DISSAPOINTED!!!!