Shipping by value

Can someone please assist. I want to set shipping by the value of items in the cart

Up to £15.00 = £2.99
£15.01-45.00 = £4.99
£45.01-99.99 = £8.99
£100.00+ FOC

All gift vouchers regardless of value if that is the only thing ordered then = £2.99

What I seem to have created is a customer option list allowing them to select the one they want. As you might guess that wasn't the intention.

Is there a way to achieve what I want?

The out of the box shipping rate provider " Manual (Fixed or By Weight and By Total)" has fields for "Order subtotal from" and "Order subtotal to".

However, it won't handle "All gift vouchers regardless of value if that is the only thing ordered ..." .
(And, I assume you also don't want to include the price of the gift vouchers in the from/to range above, when there are other items in the cart).  It will require customization (make your own plugin; you can copy that one as a start), or Shipping Director can do it - example:  You can still set up your ranges in FixedByWeightByTotal and SD can call it.  SD will "pack" items excluding gift vouchers:

OptionExit
Shipping
Items.All(HasCategory("Gift Vouchers"))
2.99

Packing
Pack exclude gift vouchers
true
Packing.FirstFitSingleBox
HasCategory("Gift Vouchers")     [this is the Exclusion Expression]

Option
Shipping
true
Shipping.FixedByWeightByTotal

With the exception of the gift vouchers that is what I thought I had set up.

This is what I have in settings:

fixedbyweightbytotalsettings.shippingbyweightbytotalenabled True
shippingratecomputationmethod.fixedbyweightbytotal.rate.shippingmethodid1 2.99
shippingratecomputationmethod.fixedbyweightbytotal.rate.shippingmethodid2 4.99
shippingratecomputationmethod.fixedbyweightbytotal.rate.shippingmethodid3 8.99
shippingratecomputationmethod.fixedbyweightbytotal.rate.shippingmethodid5 2.99

In all cases this is applicable to All stores

At Checkout. This is what is shown

Shipping method
Under £15 (£0.00)
Small packet and lower value items
£15.01-45.00 (£0.00)
Mid value items
£45.01 - 99.99 (£0.00)
Higher value items
£100+ (£0.00)
Over £100
Gift Cards Only (£0.00)
If cart is purely gift cards

RE: "This is what I have in settings"

Then you are using the "Fixed Rate" mode, rather than the "By Weight/Total" mode  (see the toggle at the top left of the page).  To use the order subtotal from/to ranges, you need to use the "By Weight/Total" mode (and add records for each range).

P.S.  I should also mention that if you really want to show those different method names (rather than having a single method called e.g. "Shipping"), then you should select "Limit shipping methods to configured ones" at the bottom of the page.  (Otherwise you will see all the methods that are  configured in 'Manage shipping methods', and all but the one matching the range will show a $0 amount.)

Many thanks for your input, I suggested all gift vouchers should be download only and therefore free of postage charges, so, that just leaves the values for items in the cart.